U.S. patent number 4,980,729 [Application Number 07/389,863] was granted by the patent office on 1990-12-25 for copying machine with improved document and copy sheet handling.
This patent grant is currently assigned to Sharp Kabushiki Kaisha. Invention is credited to Yuji Okamoto.
United States Patent |
4,980,729 |
Okamoto |
December 25, 1990 |
Copying machine with improved document and copy sheet handling
Abstract
A copying machine which comprises a document tray for
accommodating a plurality of sheet-like documents to be copied; a
first reading station at which a first of the sides of the document
is scanned; a second reading station at which the other or second
of the sides of the documetn is scanned; a document handling
mechanism including a document inverting device including a
document transport passage for inverting the document to permit the
other or second of the sides thereof to be presented to the second
reading station after the first of the sides thereof has been
presented to the first reading station; a photosensitive medium for
copying an image of each of the documents, scanned at any one of
the first and second reading stations, onto a copying sheet; an
intermediate tray for the temporary storage of the copying sheet
after the latter has been moved past a transfer station and from
which the copying sheet is subsequently transported again to the
transfer station; a sheet inverting device for turning the copying
sheet upside down before it is delivered onto the intermediate
tray; and a sheet delivery passage leading to the intermediate
tray. The transport of the document in the document transport
passage parallels the transport of the copying sheet in the sheet
delivery passage.
Inventors: |
Okamoto; Yuji (Nara,
JP) |
Assignee: |
Sharp Kabushiki Kaisha (Osaka,
JP)
|
Family
ID: |
16430167 |
Appl.
No.: |
07/389,863 |
Filed: |
August 4, 1989 |
Foreign Application Priority Data
|
|
|
|
|
Aug 10, 1988 [JP] |
|
|
63-200786 |
|
Current U.S.
Class: |
399/374 |
Current CPC
Class: |
G03B
27/6257 (20130101); G03G 15/04 (20130101); G03G
15/23 (20130101) |
Current International
Class: |
G03B
27/62 (20060101); G03G 15/23 (20060101); G03G
15/04 (20060101); G03G 15/00 (20060101); G03G
021/00 () |
Field of
Search: |
;355/308,318,319,320,321,23,24 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Grimley; A. T.
Assistant Examiner: Ramirez; Nestor R.
Attorney, Agent or Firm: Birch, Stewart, Kolasch &
Birch
Claims
I claim:
1. An automatic document recirculating system which comprises:
a document storage means for accommodating a plurality of
sheet-like documents to be copied;
a first document presenting portion for supporting thereon
documents successively drawn from said document storage means so
that one of two sides of each of said documents can be scanned;
a second document presenting portion for supporting thereon each of
said documents which has passed through said first document
presenting portion, so that the other of said two sides of each of
said documents can be scanned;
a document handling mechanism including a document inverting means
positioned between said first and second document presenting
portions for inverting each of said documents which has passed
through said first document presenting portion;
a document illuminating means supported for movement between first
and second positions which are aligned with said first and second
document presenting portions, respectively;
a drive means for driving said document illuminating means to said
first position when a document supported on said first document
presenting portion is to be illuminated and for driving said
document illuminating means to said second position when a document
supported on said second document presenting portion is to be
illuminated; and
means for causing a first document illuminated at said first
position to be inverted by said document inverting means while a
second document is being scanned for the first time by said
document illuminating means at said first position.
2. The automatic document recirculating system of claim 1, further
including means for causing said second document illuminated at
said first position to be inverted by said document inverting means
while said inverted first document is being scanned by said
document illuminating means at said second position.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a copying machine of a type
equipped with a recirculating document handling mechanism for
automatically feeding a plurality of sheet-like documents to be
copied onto a document reading station one at a time. The present
invention is particularly suited for, although not exclusively
limited to, use with sheet-like documents each having an image on
both sides thereof.
In the description to follow, the following terms used herein for
the purpose of the present invention are to be construed having the
following respective meanings.
"Duplex document": a sheet-like document which has its opposite
sides bearing respective images to be copied.
"Duplex copy": a copying or recording sheet having its opposite
sides copied with respective images.
"Simplex document"; a document which has only one side bearing an
image to be copied.
"Simplex copy": a copying or recording sheet having only one side
copied with an image.
2. Description of the Prior Art
Most of the conventional electrophotographic copying machines of
the slit exposure type in which a document to be copied is scanned
by an optical system are equipped with a recirculating document
handling mechanism (RDH) designed to feed a plurality of sheet-like
documents to be copied automatically one at a time onto a document
reading station so that each document can be read by an optical
reader held at a predetermined position.
FIG. 1 illustrates, in schematic side sectional representation, an
electrophotographic copying machine 1 equipped with a recirculating
document handling mechanism that is employed in the practice of the
prior art as well as the present invention. The electrophotographic
copying machine 1 comprises a machine housing 2 having the
recirculating document handling mechanism 3 and a document presser
plate 4 both mounted atop the machine housing 2.
In order to make duplex copies from duplex documents with page
layouts of each duplex copy identical with those of the
corresponding duplex document, it is a general practice to place a
stack of duplex documents within a document tray 5. Each of the
stacked documents within the document tray 5 is transported by
means of a feed roller 6 towards a first reading station 7 at which
the respective document can be illuminated by an illuminator lamp
10 so that information on one of the sides of such a document can
be read. After information on the respective side of the document
has been read out at the first reading station 7, such document is
turned upside down by a document inverting means 8 and is then
transported to a second reading station 9 at, which information on
the other remaining side of the document can be read out. At the
second reading station 9, this other side of the document is
illuminated by the illuminator lamp 10.
Imagewise rays of light reflected from the document at any one of
the first and second reading stations 7 and 9 can be transmitted
towards a photoreceptor drum 12 through an optical system 11 and is
then projected onto a photosensitive surface of the photoreceptor
drum 12 at exposure station 13. Since at this time the
photosensitive surface of the photoreceptor drum 12 has been
electrostatically charged by a primary corona discharger 14,
projection of the imagewise rays of light onto the photosensitive
surface of the photoreceptor drum 12 at the exposure station 13
results in a formation of an electrostatic latent image on the
photosensitive surface in complemental relationship with an image
on each side of the document. The electrostatic latent image so
formed is then developed by a developing unit 15 into a visible
toner image which is subsequently transferred at a transfer station
by the action of a transfer corona discharger 18 onto a copying
sheet that has been supplied from a sheet supply cassette 16 by
means of a sheet feed roller 17.
The copying sheet bearing the visible toner image which has been
transferred from the photosensitive surface of the photoreceptor
drum 12 is then supplied through a fixing unit 19 by which the
visible toner image can be permanently fixed to one side of the
copying sheet. In order to make a copy on the other side of the
copying sheet thereby to complete a duplexed copy, the copying
sheet having one of the sides copied with an image from one of the
sides of the duplexed document, is supplied towards an intermediate
tray 21 through a sheet inverting means 20. Thereafter, the copying
sheet once supplied to the intermediate tray 21 is drawn by a sheet
feed roller 22 out of the intermediate tray 21 and towards the
photoreceptor drum 12 for receiving a similarly visible toner
image, corresponding to an image on the remaining side of the
duplex document, from the photoreceptor drum 12 at the transfer
station on the other or remaining side of the copying sheet. After
the visible toner image has been transferred onto this other side
of the copying sheet, the latter is transported through the fixing
unit 19 so that the visible toner image can be permanently fixed
thereto and is then ejected onto a copy receiving tray 23, thereby
completing the duplex copying.
FIG. 6 comprised of FIGS. 6(a) to 6(h) illustrates the sequence of
making the duplex copies from a plurality of simplex documents, for
example, the first and second simplex documents Da and Db. It is to
be noted that, in the following description, reference character
"D" used to denote a document to be copied and to which a lower
case "a" is affixed is intended to mean a first document while the
same reference character "D" to which a lower case "b" is affixed
is intended to mean a second document to be copied subsequent to
the copying of the first document and that numerals "1" to "4"
affixed to any one of reference characters "Da" and "Db" are
intended to represent a page number of the first or second
document. For example, the first page of the first document is
designated by "Dal" and the third page of the second document is
designated by "Db3". It is also to be noted that each copying sheet
generally identified by P is shown to have its opposite sides
designated respectively by Pa and Pb in correspondence with the
first and second document Da and Db, respectively, and reference
characters "Pa" and "Pb" are affixed with one of the numerals "1"
to "4" to denote the page number of each of the documents.
In addition, for the purpose of quick reference, throughout the
accompanying drawings, particularly FIGS. 6 and 7 as well as FIG.
4, each document Da or Db is shown as affixed on its opposite sides
with numerals ("1" to "4") each representing the page number, while
each odd-numbered page is indicated by a blank triangle. Also, so
far as each copying sheet P is concerned, any one of the opposite
sides of the copying sheet P which has been copied with an image is
shown as having a numeral representative of the page number of the
document on which such image has been born while each odd-numbered
page is indicated by a blackened triangle. It is, however, to be
noted that no affix will be employed to any one of the reference
characters "D" and "P" used to denote the document and the copying
sheet where the document or the copying sheet is collectively
referred to in the description.
In order to make a duplex copy from each of the simplex documents,
as shown in FIG. 6(a), the documents D to be successively copied
are placed on the document tray 5 in a stacked form and in the
sequentially paginated order with the initial page placed atop the
stack of documents. A batch of copying sheets P is accommodated
within the sheet supply cassette 16 in a stacked form.
When duplex copying is initiated, as shown in FIG. 6(b), the first
document Da placed on the top of the stack of documents D within
the document tray 5 is transported to the first reading station 7
at which the first page Da1 of the first document Da is scanned so
that an image on the first page Da1 can be copied in any known
manner on one side Pal of the first copying sheet Pa. Then, as
shown in FIG. 6(c), the first document Da having its first page Da1
scanned at the first reading station 7 is subsequently transported
to the document inverting means 8 and, on the other hand, the
second document Db is transported to the first reading station 7 so
that a copy can be made on one side Pb3 of the second copying sheet
Pb.
As shown in FIG. 6(d), each of the first and second documents Da
and Db whose first sides have been successively scanned at the
first reading station 7 are transported past the second reading
station 9 without being scanned through the document inverting
means 8 and are returned to the document tray 5. On the other hand,
the first and second copying sheets Pa and Pb, having one side on
which a copy has been made, are successively transported through
the sheet inverting means 20 onto the intermediate tray 21 and
stacked therein. In this way, an image on one of the sides of each
of the first and second documents Da and Db has been copied on one
side of the associated copying sheet Pa or Pb.
In order to make a copy of an image on the other or opposite side
of each of the, first and second documents Da and Db on the other
or opposite side of the associated copying sheet Pa or Pb, the
first and second documents Da and Db are successively transported
again onto a reading station. As shown in FIG. 6(e), the first
document Da drawn from the document tray 5 again onto the reading
station is moved past the first reading station 7 without being
scanned and towards the document inverting means 8. Thereafter, as
shown in FIG. 6(f), at the second reading station 9, the second
page Da2 of the first document Da is scanned so that an image on
the second page Da2 of the first document Da can be copied on the
other side Pa2 of the first copying sheet Pa which has been
supplied from the lowermost position of the stack of copying sheets
within the intermediate tray 21. In a manner similar to the copying
on the first copying sheet Pa, as sequentially shown in FIGS. 6(g)
and 6(h), the fourth page Db4 of the second document Db is scanned
at the second reading station 9 so that an image of the fourth page
Db4 can be copied on the respective side Pb4 of the second copying
sheet Pb supplied from the intermediate tray 21. Thereafter, the
first and second documents Da and Db are successively returned to
the document tray 5 while the copying sheets Pa and Pb are
successively ejected onto the copy receiving tray 23 after having
passed through the fixing unit 19.
FIG. 7 comprised of FIGS. 7(a) to 7(h) illustrates the sequence of
making the duplex copies from a plurality of duplex documents, for
example, the first and second duplex documents Da and Db as is the
case with the example shown in FIG. 6.
In order to make a duplex copy from each of the first and second
duplex documents, as shown in FIG. 7(a), the documents D to be
successively copied are placed on the document tray 5 in a stacked
form and in the sequentially paginated order with the initial page
placed atop the stack of documents. A batch of copying sheets P is
accommodated within the sheet supply cassette 16 in a stacked
form.
When duplex copying is initiated, as shown in FIG. 7(b), the first
document Da placed on the top of the stack of documents D within
the document tray 5 is transported to the first reading station 7
at which the first page Da1 of the first document Da is scanned so
that an image on the first page Da1 can be copied in any known
manner on one side Pal of the first copying sheet Pa. Then, as
shown in FIG. 7(c), the first document Da having its first page Da1
scanned at the first reading station 7 is subsequently transported
to and temporarily held at the document inverting means 8 while the
first copying sheet P2, having the image copied on one side Pal
thereof is transported through the sheet inverting means 20 to the
intermediate tray 21.
Then, as shown in FIG. 7(d), the first document Da having passed
through the document inverting means 8 is transported to the second
reading station 9 at which the second page Da2 of the first
document Da is scanned so that an image on the second page Da2
thereof can be copied on the other side Pa2 of the first copying
sheet Pa which has been supplied from the intermediate tray 21. The
first document Da having both its sides scanned at the first and
second reading stations 7 and 9, respectively, at different timings
is subsequently returned to the document tray 5 while, on the other
hand, the first copying sheet P2, having both its sides copied with
the images on the first and second pages Da1 and Da2 of the first
document Da, is ejected through the fixing unit 19 onto the copy
receiving tray 23. It is to be noted that, when the first document
Da is returned to the document tray 5, the first document Da is
inserted in between the bottom of the document tray 5 and the
lowermost member of the stack of documents in the document tray
5.
After the first document Da has been so returned to the document
tray 5, images on the remaining opposite side of the second
document Db are successively copied on the respective opposite side
of the second copying sheet Pb in a manner similar to the copying
of the images of the first document Da on the first copying sheet
P3, and as sequentially shown in FIGS. 7(e) to 7(h).
According to the first mentioned duplex copying method shown in and
described with reference to FIG. 6, each document D is required to
be transported twice into the passages in the recirculating
document handing mechanism 3 and, therefore, there is the
possibility that the document D may be damaged. Also, during a
period in which the document D is circulated once from the first
reading station 7 to the second reading station 9 through the
document transport passage, the associated copying sheet P is
required to be retained temporarily at the intermediate tray and,
therefore, one cycle of the duplex copying operation tends to take
a relatively long time to complete. In addition, the intermediate
tray must have a size required to accommodate the plural copying
sheet generally equal in number to the maximum possible number of
documents to be copied and, therefore, the utilization of the
limited space available within the machine housing tends to be
adversely affected
On the other hand, according to the second mentioned duplex copying
method shown in and described with reference to FIG. 7, each
document may be once transported into the passages in the
recirculating document handling mechanism 3 and, therefore, the
possibility of the document being damaged can be advantageously
minimized. Also, the intermediate tray may have a size sufficient
to accommodate at least a single copying sheet since only one
copying sheet is transported to the intermediate tray during one
cycle of the duplex copying operation. Therefore, the utilization
of the limited space available within the machine housing can be
advantageously maximized and, hence, the length of time required to
complete a copying job can be advantageously reduced.
However, after the copying of the image on one side of the document
D onto one side of the copying sheet P, the copying sheet P is
required to be transported through the sheet inverting means 20 to
the intermediate tray and to be subsequently drawn out from the
intermediate tray in readiness for the copying of an image on the
remaining other side of the document onto the corresponding other
side of the copying sheet. During the period in which the copying
sheet is circulated past the intermediate tray, the document D is
required to be temporarily held in the document inverting means
and, at this time, no scanning operation can take place. Therefore,
the second mentioned prior art duplex copying method has a
disadvantage in that each cycle of the duplex copying operation
takes a relatively long time and, therefore, the utilization of the
time required to complete a copying job cannot be maximized.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been devised with a view to
substantially eliminating the above discussed problems inherent in
the prior art duplex copying machines and has for its object to
provide an improved copying machine equipped with a document
handling mechanism that is effective to maximize the utilization of
the time required to complete a copying job and, therefore, to
accomplish each cycle of the duplex copying operation in a reduced
length of time.
In order to accomplish the above described object, the present
invention provides a copying machine which comprises a document
storage means for accommodating a plurality of sheet-like documents
to be copied; a first document presenting portion for supporting
thereon the documents successively drawn from the document storage
means so that one of the sides of each of the documents can be
scanned; a second document presenting portion for supporting
thereon each of the documents which has been passed through the
first document presenting portion, so that the other or remaining
opposite side of each of the documents can be scanned; And a
document handing mechanism including a document inverting means
positioned between the first and second document presenting
portions for inverting each of the documents; a photosensitive
medium for copying an image of each of the documents, scanned at
any one of the first and second document presenting portions, onto
a copying sheet; an intermediate storage means for the temporary
storage of the copying sheet after the latter has been moved past
the photosensitive medium and from which the copying sheet is
subsequently transported again to the photosensitive medium; a
sheet inverting means positioned between the photosensitive medium
and the intermediate storage means for turning the copying sheet
upside down; the document handling mechanism having a document
transport passage means; and a sheet transport passage means, the
document and copying sheet being moved along the document transport
passage means and the sheet transport passage means
simultaneously.
According to the present invention, the copying machine is provided
with a recirculating document handling mechanism mounted atop the
machine housing. The recirculating document handling mechanism has
a document transport passage means for transporting the documents
successively from the document storage means back to the document
storage means through the first document presenting portion, then
through a document inverting means and finally through the second
document presenting portion. Each of the documents when transported
to the first document presenting portion has one of its sides
scanned and has the other of its sides scanned subsequently at the
second document presenting portion after it has been turned upside
down by the document inverting means.
At each of the first and second document presenting portions,
imagewise rays of light reflected from any one of the respective
sides of the document which has been scanned are projected onto the
photosensitive medium to form on the photosensitive medium an image
corresponding to the image on the respective side of the document,
which image is subsequently copied on a first side of the copying
sheet.
Within the machine housing, there is formed a sheet transport
passage means for transporting each copying sheet from the
photosensitive medium back to the photosensitive medium through the
sheet inverting means and then through the intermediate storage
means. By the provision of this sheet transport passage means, the
copying sheet having one side copied with an image is turned upside
down by the sheet inverting means and is then temporarily stored in
the intermediate storage means, after which the copying sheet is
transported again to the photosensitive medium so that the image
can be copied on the opposite or second side thereof.
In accordance with an essential feature of the present invention,
during duplex copying, the documents successively transported
through the document transport passage means within the
recirculating document handling mechanism and the copying sheets
having their opposite sides onto which images are to be copied,
which sheets are transported along a sheet transport passage means
within the machine housing, are transported simultaneously through
the document and sheet transport passage means respectively. In
other words, the transport of the document through the document
transport passage means within the recirculating document handling
mechanism parallels the transport of the copying sheet through the
sheet transport passage means within the machine housing.
Accordingly, the length of time required to complete the duplex
copying with respect to a single copying sheet can be
advantageously reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
This and other objects the present invention will become clear from
the following description taken in conjunction with a preferred
embodiment thereof with reference to the accompanying drawings, in
which:
FIG. 1 is a schematic side sectional view of a copying machine
equipped with a recirculating document handing mechanism (RDH),
which machine is utilized in the prior art system as well as in the
system of the present invention;
FIG. 2 is a schematic side sectional view, on an enlarged scale, of
the recirculating document handing mechanism shown in FIG. 1;
FIG. 3 is a circuit block diagram showing an electric control
device for controlling both the copying machine and the
recirculating document handing mechanism;
FIG. 4, comprised of FIGS. 4(a) to 4(f), illustrates the sequence
of duplex copying executed according to one preferred embodiment of
the present invention;
FIG. 5 is a flowchart showing a program executed in the copying
machine, equipped with the recirculating document handling
mechanism, to make duplex copies from duplex documents;
FIG. 6, comprised of FIGS. 6(a) to 6(h), illustrates the sequence
of making duplex copies from simplex documents according to one
example; and
FIG. 7, comprised of FIGS. 7(a) to 7(h), illustrates the sequence
of making duplex copies from duplex documents according to another
example.
DETAILED DESCRIPTION OF THE INVENTION
Before the description of the present invention proceeds, it is to
be noted that like parts are designated by like reference numerals
throughout the accompanying drawings. It is also to be noted that
the copying machine equipped with the recirculating document
handling mechanism shown in and described with reference to FIG. 1
in connection with the prior art examples can be utilized in the
practice of the present invention.
Referring to FIG. 1, there is schematically shown an
electrophotographic copying machine 1 which comprises the machine
housing 2 having a first transparent plate 24 that defines the
first reading station 7, a second transparent plate 25 that defines
the second reading station 9, the recirculating document handling
mechanism 3 and the document pressure plate 4 for covering and
pressing a document having a substantial thickness, all mounted
atop the machine housing 2. In addition to the first and second
transparent plates 24 and 25, a third transparent plate 26 is also
mounted atop the machine housing 2 in register with the pressure
plate 4 to support thereon the document to be copied. The pressure
plate 4 defines a third reading station and is supported for
pivotal movement between opened and closed positions and, when in
the closed position, covers and presses the document against the
third transparent plate 26.
The first transparent plate 24 defining the first reading station 7
is positioned immediately below a first support barrel 27 of right
cylindrical shape forming a part of the recirculating document
handling mechanism 3. On the other hand, the second transparent
plate 25 defining the second reading station 9 is positioned
immediately below a second support barrel 28 of right cylindrical
shape forming another part of the recirculating document handling
mechanism 3.
The details of the recirculating document handling mechanism 3 are
best shown in FIG. 2. The stack of documents D accommodated in the
document tray 5 are successively drawn out from the document tray 5
one at a time in the order from the uppermost member of the
documents D by the action of the document feed roller 6, driven by
a motor M1 in a direction shown by the arrow 30, and is then fed
towards a ruffling roller assembly 31 comprised of upper and lower
rollers 32 and 33 adapted to be driven in the same direction so
that only a single document can be transported therethrough.
Four transport roller pairs 35, 36, 37 and 38 are disposed along a
transport passage 34. All of these transport roller pairs 35 to 38
are operatively coupled so that, when a motor M2 drives one of the
transport roller pairs, for example, the transport roller pair 36
as shown, the remaining roller pairs 35, 37 and 38 can be driven in
synchronism with the roller pair 36. By the action of these
transport roller pairs 35 to 38, the document D can be transported
along the document transport passage 34 in a direction shown by the
arrow 39. The document transport passage 34 has a plurality of
detector elements S1 and S2, for example, photoelectric detector
elements, disposed therealong in spaced relationship with each
other in the detection of the passage of the document D
therethrough. In the vicinity of an exit of the document transport
passage 34 adjacent the first support barrel 27, a registering
roller pair 42 is disposed, one of the registering rollers 42 being
adapted to be drivingly coupled with a drive shaft (not shown)
through a clutch. By controlling ON and OFF states of the clutch,
the registering roller pairs 42 can be selectively driven and
halted thereby to control the timing at which, the document D can
be transported to the first support barrel 27. The control of the
timing at which the document D is transported towards the first
support barrel 27 is carried out in synchronism with the control of
the timing at which the copying paper P is transported towards the
photoreceptor drum 12. Accordingly, as will be described later, the
arrival at a transfer station of a visible toner image
corresponding to the electrostatic latent image on the
photoreceptor drum 12, which has been formed as a result of the
scanning of an image on one side of the document D, can be
synchronized with the arrival of the copying sheet P at the
transfer station so that the visible toner image can be transferred
onto the copying sheet P in the right position.
The first support barrel 27 has its outer peripheral surface formed
with suction ports that are communicated with a suction means
through the hollow of the first support barrel 27. Therefore, when
and so long as the suction means is in operation, the document D
transported to the first support barrel 27 can be retained on the
outer peripheral surface of the first support barrel 27 while
turned therearound. This first support barrel 27 is adapted to be
driven by a motor M3 so as to rotate in one direction shown by the
arrow 43 and, therefore, the document D turned around and retained
on the first support barrel 27 is, while sandwiched between the
first support barrel 27 and follower rollers 44 and 45, moved
immediately above the first transparent plate 24 so that one of the
sides of the document 27 can be scanned by the illuminator lamp 10,
shown in FIG. 1. Imagewise rays of light reflected from such one
side of the document D are transmitted through the first
transparent plate 24 and in turn projected onto the photoreceptor
drum 12 in the manner as hereinbefore described and is well
know.
The document D having one side having been scanned at the first
reading station 7 immediately above the first transparent plate 24
is, while sandwiched between the first support barrel 27 and a
follower roller 46, moved past a deflector pawl 47 ,which is
supported for pivotal movement between solid-line and phantom
positions. When and long as the deflector pawl 47 is held in the
phantom position shown by the phantom line in FIG. 2, the document
D can be, while sandwiched between the first support barrel 27 and
a follower roller 48, transported again to the first reading
station 7 so that the same side of the document D can be again
scanned. On the other hand, when, the deflector pawl 47 is switched
over to the solid-line position shown by the solid line in FIG. 2,
the document D can be transported through a transport passage 49
towards the document inverting means 8. The switching in position
of the deflector pawl 47 between the solid-line and phantom
positions can be accomplished by the operation of a solenoid unit
SOL1.
The document inverting means 8 comprises a detector element S3, a
pair of transport rollers 50 and 51, a deflector pawl 52, a
transport passage 53 and a pair of reversible transport rollers 54
and 55. The document D transported into the transport passage 49 is
in turn transported by the transport rollers 50, 51, 54 and 55 into
the transport passage 53 in the document inverting means 8. During
the transport of the document D into the transport passage 53, the
deflector pawl 52 is held at a position shown by the phantom line
in FIG. 2. When a leading end of the document D with respect to the
direction of transport thereof through the transport passage 49
moves past the detector element S3, and after a predetermined time
subsequent to the detection of the passage of the leading end of
the document D past the detector element S3, an operation for
turning the document D upside down is initiated. In other words,
the transport rollers 54 and 55 are driven by a motor M4 in a
direction required for the document D to be moved back towards the
position where the deflector pawl 52 is installed and, at the same
time, the deflector pawl 52 is switched over to another position
shown by the solid line in FIG. 2, wherefore the document D can be
transported past the deflector pawl 52 towards a transport passage
56. The switching in position of the deflector pawl 52 can be
accomplished by the operation of a solenoid unit SOL2.
The document transported into the transport passage 56 is, while
sandwiched between the roller 51 and a transport roller 57
supported for movement close to and away from the roller 51 and
rotatable in contact with the roller 51, transported towards the
second support barrel 28. The movement of the roller 57 in a
direction close to and away from the roller 51 can be controlled by
the operation of a solenoid unit SOL3. When the passage of the
trailing end of the document D with respect to the direction of
transport thereof towards the second support barrel 28 past the
transport rollers 51 and 57 is detected by a detector element S4, a
registering roller pair 58 is controlled in a manner similar to the
registering roller pair 42 with the document D consequently
transported to the second support barrel 28.
The second support barrel 28 is of a construction generally
identical with the first support barrel 27 and is adapted to retain
the document D on the outer peripheral surface thereof by means of
a suction force developed by a similar suction means. This second
support barrel 28 is adapted to be driven by a motor M5 in one
direction shown by the arrow 59, and the document D retained on the
outer peripheral surface of the second support barrel 28 is, while
sandwiched between the second support barrel 28 and follower
rollers 60 and 61, moved past the second reading station 9
immediately above the second transparent plate 25. Since at this
time the document D has been turned upside down by the document
inverting means 8, the opposite side of the document D is presented
to the second reading station 9. For scanning such other opposite
side of the document D, the optical system 11 (See FIG. 1)
including the illuminator lamp 10, is moved from a first position
in register with the first reading station 7 to a second position
in register with the second reading station 9. With the optical
system 11 held at the second position, this other opposite side of
the document D, this time presented to the second reading station
9, can be scanned by the illuminator lamp 10 so that an image on
this other opposite side of the document D can be eventually formed
on the copying sheet in a manner well know to those skilled in the
art.
The document having such other side scanned at the second reading
station 9 immediately above the second transparent plate 25 is,
while sandwiched between the second support barrel 28 and a
follower roller 62, transported towards a deflector pawl 63. So
long as the deflector pawl 63 is held at a phantom position shown
by the phantom line in FIG. 2, the document D can be, while
sandwiched between the second support barrel 28 and a follower
roller 64, transported again to the second reading station 8 so
that the same side of the document D can be again scanned. On the
other hand, when the deflector pawl 63 is switched over to the
solid-line position shown by the solid line in FIG. 2, the document
D can be transported towards a transport passage 67 by the action
of roller pairs 65 and 66. The switching in position of the
deflector pawl 63 between the solid-line positions can be
accomplished by the operation of a solenoid unit SOL4.
The document D transported into the transport passage 67 is
subsequently transported towards the document tray 5 by means of a
delivery means 68 which comprises a drive roller 69 and three
driven rollers 70, 71 and 72, a generally endless delivery belt 73
trained around these rollers 69 to 72, and a follower roller 74
adapted to sandwich the document D between it and a portion of the
delivery belt 73. When the leading end of the document D with
respect to the direction of transport thereof towards the document
tray 5 along the transport passage 67 moves past a detector element
S5, the drive roller 69 is driven by a motor M6 so as to drive the
delivery belt 73 in one direction shown by the arrow 75. The
document D is, therefore, while sandwiched between that portion of
the delivery belt 73 and the follower roller 74, transported
towards the document tray 5 and is inserted in between the bottom
of the document tray 5 and the lowermost member of the stacked
documents in the document tray 5. In this way, both opposite sides
of each document D can be scanned at the first and second reading
stations 7 and 9 successively.
When the document presented at one of the first reading station 7,
the second reading station 8 and the third reading station 29 is
scanned by the illuminator lamp 10, imagewise rays of light
reflected therefrom are projected by means of the optical system 11
and along an optical path 79 onto the photosensitive surface of the
photoreceptor drum 12 at the exposure station 13 to form an
electrostatic latent image thereon. This optical system 11 may be
of any known construction and, as so far illustrated, comprises, in
addition to the illuminator lamp 10, reflector mirrors 80, 81 and
82, a zoom lens assembly 83 and a reflector mirror 84.
Referring again to FIG. 1, during each complete rotation of the
photoreceptor drum 12, the photosensitive surface of the
photoreceptor drum 12 is moved sequentially past the charging
station at which the photosensitive surface is electrostatically
charged by the primary corona discharger 14; the exposure station
13 at which the imagewise rays of light reflected from the document
presented to any one of the first reading station 7, the second
reading station 9 and the third reading station 29 and therefore
carrying the image of the document are projected onto the
photosensitive surface to form an electrostatic latent image
thereon; a developing station at which the developing unit 15 is
disposed for developing the electrostatic latent image into a
visible toner image; the transfer station at which the transfer
corona discharger 18 is installed for assisting the transfer of the
visible toner image onto a copying sheet P which has been supplied
from the supply cassette 16 towards the transfer station by the
sheet feed roller 17 by way of a transport passage 86; a separating
station at which the copying sheet having the visible toner image
transferred thereto is separated from the photoreceptor drum 12;
and a cleaning station at which residue toner and residue
electrostatic, charge, both remaining on the photosensitive surface
of the photoreceptor drum 12, can be removed in readiness for the
next cycle of copying operation.
It is to be noted that the illustrated copying machine includes, in
addition to the sheet supply cassette 16, sheet supply cassettes
87, 88 and 89 for accommodating respective batches of copying
sheets of different sizes, which cassettes 16, 87, 88 and 89 are
selectively brought into operation one at a time so that the
copying sheets of selected size can be successively supplied
towards the sheet transport passage 86 by means of the sheet feed
roller 17, 90, 91 or 92.
The transport passage 86 has a detector element S6 and a
registering roller pair 94 both installed therealong. Therefore,
when the leading end of the copying sheet P with respect to the
direction of transport thereof towards the photoreceptor drum 12
along the transport passage 86 is moved past the detector element
S6, the rotation of the registering roller pair 94 is so controlled
simultaneously with the control of the registering roller pair 42
or 58 in the recirculating document handling mechanism 3 that the
arrival of the copying sheet P at the transfer station can be
synchronized with the arrival of the visible toner image, carried
by the photoreceptor drum 12, at the transfer station.
The copying sheet P which has been separated from the photoreceptor
drum 12 at the separating station is conveyed towards the fixing
unit 19 through a conveyance means 95. When simplex copying is done
on the copying sheet, the copying sheet P having passed through the
fixing unit 19 is subsequently ejected onto the copy receiving tray
23 through an ejecting passage 107. However, when duplex copying is
to be done on the copying sheet P, the copying sheet P, having
passed through the fixing unit 19 is delivered into the sheet
inverting means 20 without being ejected onto the copy receiving
tray 23.
The sheet inverting means 20 includes a branch passage 102 branched
off from the ejecting passage 107, a first delivery passage 103, a
second delivery passage 104, a third delivery passage 105, a first
deflector pawl 97 disposed at the junction between the branch
passage 102 and the ejecting passage 107, a second deflector pawl
98 disposed at the junction between the first, second and third
delivery passages 103, 104 and 105, a delivery roller pair 100
disposed along the first delivery passage 103, and a reversible
delivery roller pair 101 disposed along the second delivery passage
104. When duplex copying is to be made on the copying sheet P, the
first deflector pawl 97 is held at a phantom position shown by the
phantom line in FIG. 1 and, therefore, the copying sheet having one
side copied with the image of one side of the document is guided
into the branch passage 102 and is then transported by the deliver
roller pair 100 towards the first delivery passage 103. Also, since
the second deflector pawl 98 is held at a phantom position shown by
the phantom line in FIG. 1 at this time, the copying sheet P can be
further delivered into the second delivery passage 104. When the
trailing end of the copying paper P with respect to the direction
of transport thereof towards the second delivery passage 104 moves
past a detector element S7, and after a predetermined time
subsequent to the passage of the trailing end of the copying sheet
P past the detector element S7, the delivery roller pair 101 are
reversibly driven in a direction required for the copying sheet P
to be transported back towards the first delivery passage 103.
However, since at this time the second deflector pawl 98 is
switched over to a solid-line position shown by the solid line in
FIG. 1, the copying sheet P tending to be transported from the
second delivery passage 104 towards the first delivery passage 104
as a result of the reversed rotation of the delivery roller pair
101 is guided into the third delivery passage 105 and is then
supplied onto the intermediate tray 21 by means of a drawing roller
pair 106.
The copying sheet P once accommodated within the intermediate tray
21 is again supplied by the sheet feed roller 22 into the transport
passage 86 by way of the transport passage 108. The copying sheet P
so transported into the transport passage 86 is subsequently
delivered towards the photoreceptor drum 12 by the registering
roller pair 94 for receiving a visible toner image on the other
side of the copying sheet P. In this way, images of either side of
the document D or one side of the respective documents D can be
copied on the respective opposite sides of the copying sheet P,
which sheet P is subsequently transported through the ejecting
passage 107 onto the copy receiving tray 23. At this time, the
first deflector pawl 97 has been switched over to the solid-line
position shown by the solid line in FIG. 1.
FIG. 3 illustrates a block circuit diagram of a control unit used
to control both of the copying machine 1 and the recirculating
document handling mechanism 3. As shown therein, the various drive
motors such as designated by M1, M2, M3 and so on for driving the
transport rollers and the support barrels are electrically
connected with a motor drive circuit 110; the various clutches for
controlling the synchronism between the transportation of the
document D within the recirculating document handling mechanism 3
and the transportation of the copying sheet within the machine
housing 2 are electrically connected with a clutch drive circuit
111; and the various solenoid units such as designated by SOL1,
SOL2 and so on for activating the various deflector pawls in the
associated transport and delivery passages are electrically
connected with a solenoid drive circuit 112. These drive circuits
110, 111 and 112 as well as a direct current power source (D.C.)
113, and the various detector elements, such as designated by S1,
S2 and so on for detecting the document D and the copying sheet P
being transported, as well as an optical system drive circuit 114
for driving the optical system 11, various keys 116 disposed on a
control panel 115 on the machine housing 2 and a display drive
circuit 117 for driving display devices disposed on the control
panel 115 are electrically connected with an input/output interface
circuit 118.
The interface circuit 118 is in turn connected with a central
processing unit (CPU) 119 comprised of a microcomputer for
outputting respective detection signals from the various detector
elements and also for controlling the various drive circuits 110,
111, 112, 114 and 117 in response to control signals outputted from
the central processing unit 119. The central processing unit 119 is
connected with a read-only memory ROM) 120 and a random access
memory (RAM) 121 and performs a control operation according to a
control program stored in the read-only memory 120. The random
access memory 121 is used as a work area for various counters and
timers necessitated to control the copying operation. The interface
circuit 118 is operable to drive the optical system 11 through the
optical system drive circuit 114 and also to control the selective
switching on and off of the illuminator lamp 10 at each of the
first, second and third reading stations 7, 9 and 29. Also, the
interface circuit 118 is adapted to receive input signals from the
keys 116 on the control panel 115 and to activate the display drive
circuit 117 so that the status of the copying operation then taking
place can be indicated by means of the display devices 122 on the
control panel 116. This interface circuit 118 is also connected
with select switches SSW1, SSW2, SSW3 and SSW4 for selecting one of
the copying modes which may include a simplex-to-simplex mode in
which an image on one side of a simplex document can be copied on
one side of a copying sheet, a simplex-to-duplex mode in which an
image on one side of each of two simplex documents can be copied on
opposite sides of one copying sheet, a duplex-to-simplex mode in
which images on the opposite sides of a duplex document can be
copied on one side of a copying sheet, and a duplex-to-duplex mode
in which images on the opposite sides of a duplex document can be
copied on the opposite sides of a copying sheet
FIG. 4, comprised of FIGS. 4(a) to 4(f), illustrates the sequence
of making the copies from a plurality of documents, for example,
the first and second duplex documents Da and Db, performed with the
use of the copying machine 1 equipped with the recirculating
document handling mechanism 3 according to the present
invention.
As shown in FIG. 4(a), the documents D to be successively copied
are placed on the document tray 5 in a stacked form and in the
sequentially paginated order with the initial page placed atop the
stack of the documents. A batch of copying sheets P is accommodated
within the sheet supply cassette 16 in a stacked form.
When copying is initiated, as shown in FIG. 4(b), the document feed
roller 6 is brought into contact with the first document Da placed
on the top of the stack of documents D within the document tray 5
so that the first document Da can be delivered into the transport
passage 34. The first document Da in the transport passage 34 is
supported by the first support barrel 27 and is moved past the
first reading station 7 at which the first page Da1 of the first
document Da is scanned, that is, illuminated by the illuminator
lamp 10, so that an image on the first page Da1 can be subsequently
projected onto the photosensitive surface of the photoreceptor drum
12 to form an electrostatic latent image thereon The electrostatic
latent image so formed is thereafter developed into a visible toner
image which is in turn transferred at the transfer station onto one
side of the copying sheet Pa.
Then, as shown in FIG. 4(c), the first document Da having its first
page Da1 scanned at the first reading station 7 is subsequently
transported to the transport passage 53 of the document inverting
means 8 and, on the other hand, the first copying paper Pb is
transported through the transport means 95 to the fixing unit 19 at
which the visible toner image transferred onto the first copying
sheet Pa in the manner as hereinabove described can be permanently
fixed thereon. The copying sheet Pa having the image permanently
fixed thereon is subsequently delivered to the sheet inverting
means 20.
Within the sheet inverting means 20, the first copying sheet Pa is
transported through the delivery passages 102, 103, 104 and 105
towards the intermediate tray 21. When the trailing end of the
first document Da being transported towards the document inverting
means is moved past the first reading station 7, the second
document DB accommodated in the document tray 5 is drawn out from
the document tray 5 by the feed roller 6 and is then transported
towards the first support barrel 27 through the transport passage
34. At this time, the first document Da is held within the document
inverting means 8 while the first copying sheet Pa is held in a
condition ready to move past the intermediate tray 21 and then to
be transported by the feed roller 22 onto the transport passage 86
again. During a period in which the first document Da is held
within the document inverting means 8, the second document Db is
supported around the second support barrel 27 so as to move past
the first reading station 7. At the first reading station 7, the
third page Db3 of the second document Db is illuminated by the
illuminator lamp 10 so that an image on the third page Db3 of the
second document Db can be projected onto the photosensitive surface
of the photoreceptor drum 12 to form an electrostatic latent image
thereon, which latent image is subsequently developed into a
visible toner image. This visible toner image is then transferred
at the transfer station onto one side of the second recording sheet
Pb which has been supplied to the transfer station from the sheet
cassette 16 by means of the feed roller 17.
The second document Db having one side forming the third page Db3
which has been scanned at the first reading station 7 is thereafter
transported to the document inverting means 8 as shown in FIG.
4(d). The first document Da held in the document inverting means 8
before the second document Db is transported into the document
inverting means 8 is transported to the second support barrel 28,
conceding the document inverting means 8 to the second document Db.
In other words, after the first document Da has moved past the
document inverting means 8, the second document Db is transported
into the document inverting means 8. The second recording sheet Pb
having one side, that is, the third page Db3, onto which the
visible powder image has been transferred is transported through
the transport means 95 to the fixing unit at which such visible
toner image is permanently fixed, and is thereafter delivered to
the intermediate tray 21 through the delivery passages 102 to 105
of the sheet inverting means 20.
The first document Da transported to the second support barrel 28
is, while turned therearound, moved past the second reading station
9. At this second reading station 9, the opposite side, that is,
the second page Da2, of the first document Da is illuminated by the
illuminator lamp 10 of the optical system that has been moved from
the first reading station 7 so that an image of the second page Da2
of the first document Da can be projected onto the photosensitive
surface of the photoreceptor drum 12 to form an electrostatic
latent image. This electrostatic latent image is subsequently
developed into a visible toner image which is transferred at the
transfer station onto the other side of the first copying sheet Pa
which has been transported to the transfer station by the feed
roller 22 through the transport passage 108 and then through the
transport passage 86.
After the second page Da2 of the first document Da has been scanned
at the second reading station 9, as shown in FIG. 4(e), the first
document Da is returned to the document tray 5 via the document
delivery means 68 in the manner as hereinbefore described. On the
other hand, the first copying sheet Pa having its opposite sides
copied with the respective images is, without being delivered into
the sheet inverting means 20, ejected through the transport means
95 onto the copy receiving tray 23.
When the trailing end of the first document Da being transported
moves past the second reading station 9, the second document Db
temporarily held in the document inverting means 8 is transported
towards the second support barrel 28. While retained by the second
support barrel 28, the second document Db is moved past the second
reading station 9. At this second reading station 9, the other
side, that is, the fourth page Db4, of the second document Db, is
scanned with an image of the fourth page Db4 consequently projected
onto the photosensitive surface of the photoreceptor drum 12 to
form an electrostatic latent image. This electrostatic latent image
corresponding to the image on the fourth page Db4 of the second
document Db is subsequently developed into a visible toner image
which is eventually transferred onto the opposite side of the
second copying sheet Pb then transported from the intermediate tray
21 by means of the feed roller 22 via the transport passage 108 and
then via the transport passage 96.
The second document Db having been scanned at the second reading
station 9 is returned to the document tray 5 through the document
delivery means 68 and is inserted in between the bottom of the
document tray 5 and the lowermost sheet of the stack of the
documents D. On the other hand, the second copying sheet having the
images copied on the opposite sides thereof is, without being
delivered to the sheet inverting means 20, ejected through the
ejecting passage 107 onto the copy receiving tray 23 and stacked
above the first copying sheet Pa then resting on the copy receiving
tray 23. In this wa the duplex copying of the two documents Da and
Db is completed. Accordingly, the first duplex copy will show that
the respective images of the first and second pages Da1 and Da2 of
the first document Da are copied on the opposite sides of the first
copying sheet Pa, and the second duplex copy will show that the
respective images of the third and fourth pages Db3 and Db4 of the
second document Db are copied on the opposite sides of the second
copying sheet Pb.
After the first and second documents Da and Db have been completely
copied on the first and second copying sheets Pa and Pb in the
manner as hereinbefore described, as shown in FIG. 4(f), the
documents D returned to the document tray 5 are stacked in the same
way as they had been at the start of the copying operation, that
is, in the sequentially paginated order with the initial page
placed atop the stack of the documents Accordingly, the next
succeeding copying operation can be initiated, if desired, or the
stack of documents can be removed from the document tray 5, with no
need to rearrange the documents within the document tray 5. On the
other hand, the resultant duplex copies on the copy receiving tray
23 are stacked in the sequentially paginated order with the initial
page placed at the bottom of the stack of the resultant duplex
copies
FIG. 5 illustrates a flowchart of a control program used to control
the copying of the images of the two documents Da and Db on the
opposite sides of a copying sheet. Referring to FIG. 5, when the
duplex copying is initiated, and at step S1, the first document Da
is transported from the document tray 5 towards the first support
barrel 27 and, then at step S2, the supply of the first copying
sheet Pa from the sheet cassette 16 is initiated. At subsequent
step S3, a decision is made to determine if the supply of the
copying sheet Pa to the transfer station is regulated by the
registering roller pair 94 so that the visible toner image formed
on the photosensitive surface of the photoreceptor drum 12, as a
result of the document scanning operation as will be described
later, can be registered at the transfer station with the first
copying sheet Pa. If the supply of the copying sheet Pa to the
transfer station has not yet been so regulated, step S3 is repeated
and step S4 takes place when and after the supply of the copying
sheet Pa to the transfer station has been regulated by the
registering roller pair 94.
At step S4, the illuminator lamp 10 of the optical system 11 then
stationed in the vicinity of the first reading station 7 is
switched on to initiate the document scanning operation, followed
by step S5 at which a decision is made to determine if one side of
the first document Da being moved past the first reading station 7
is scanned. If it has not yet been scanned, step S5 is repeated
until such one side of the first document Da is completely scanned.
Thereafter, and at step S6, the illuminator lamp 10 is switched off
consequentially upon the completion of the scanning of the first
document Da, followed by step S7 at which the document Da having
one side completely scanned is transported to the document
inverting means 8. At step S8, the second document Db is
transported from the document tray 5 towards the first support
barrel 27, followed by step S9 at which the first copying sheet Pa
having one side copied with the image on one side of the first
document Da is delivered to the intermediate tray 21 through the
sheet inverting means 20. At subsequent step S10, the supply of the
second copying sheet Pb from the cassette 16 is initiated, followed
by step S11 at which a decision is made in a manner similar to the
decision step S3 to determine if the supply of the second copying
sheet Pb to the transfer station is regulated by the registering
roller pair 94 so that the visible toner image formed on the
photosensitive surface of the photoreceptor drum 12 as a result of
the document scanning operation can be registered at the transfer
station with the second copying sheet Pb. This step S11 is repeated
unless the supply of the second copying sheet Pb to the transfer
station is regulated by the registering roller pair 94, but when
and after it has been regulated, the program flow advances to step
S12.
At step S12, the illuminator lamp 10 is switched on to initiate the
scanning of the second document Db, followed by step S13 at which a
decision is made to determine if the second document Db moving past
the first reading station 7 has been scanned. If it has not yet
been scanned, step S13 is repeated until the second document Db is
completely scanned. After the complete scanning of the second
document Db, step S14 takes place to switch the illuminator lamp 10
off and, at step S15, the optical system 11 is moved from the first
reading station to the second reading station 9. At step S16, the
second document Db having one side completely scanned at the first
reading station is transported to the document inverting means 8,
followed by step S17, at which the first document Da is transported
from the document inverting means 8 towards the second support
barrel 28, conceding the document inverting means 8 to the second
document Db. At subsequent step S17, the second copying sheet Pb
having one side copied with the image is delivered towards the
intermediate tray 21 through the sheet inverting means 20 and, at
step S20, the supply of the first copying sheet Pa, having one side
copied with the image and held at the intermediate tray 21, is
initiated the transfer station. Then, at step S21, a decision is
made to determine, in a manner similar to the decision step S3 or
S11, if the supply of the copying sheet to the transfer station is
regulated, and if it has not yet been regulated, step S20 is
repeated before the program flow advance to step S21.
At step S21, the illuminator lamp 10 is switched on to initiate the
scanning operation at the second reading station 9. Then, at step
S22, a decision is made to determine if the other side of the first
document Da, being moved past the second reading station 9, has
been scanned. If the scanning of the other side of the first
document Da at the second reading station 9 has not yet been
finished, step S22 is repeated before the program flow advances to
step S23. Consequently, upon the completion of the scanning of the
other side of the first document Da, the illuminator lamp 10 is
switched off at step S23 and, on the other hand, at step S24, the
first document Da having its opposite sides having been completely
scanned is returned to the document tray 5. Subsequently, at step
S25, the second document Db temporarily held at the document
inverting means 8 is transported towards the second support barrel
28, followed by step S26 at which the first copying sheet Pa having
its opposite sides copied with the images is ejected onto the copy
receiving tray 23. Then, at step S27, the supply of the second
copying sheet having one side copied with the image and temporarily
held at the intermediate tray 21 is initiated, followed by step S28
at which a decision is made in a manner similar to the decision
step S3, S11 or S20 to determine if the supply of the second
copying sheet Pb towards the transfer station is regulated. Unless
the supply of the second copying sheet Pb is regulated, step S28 is
repeated.
Thereafter, at step S29, the illuminator lamp 10 is switched on
and, at step S30, a decision is made to determine if the other side
of the second document Db, being moved past the second reading
station 9, has been scanned. If it has not yet been scanned, step
S30 is repeated before the program flow advances to step S31.
Consequently, upon the completion of the scanning of the other side
of the second document Db, at step S31, the illuminator lamp 10 is
switched off and the optical system 11 is again moved from the
second reading station 9 back to the first reading station 7. At
subsequent step S32, the second document Db having its opposite
sides completely scanned is returned to the document tray 5 and, at
step S33, the second copying sheet Pb having its opposite sides
copied with the images is ejected onto the copy receiving tray 23.
In this way, the duplex copying of the duplex documents Da and Db
on the duplex copying sheets Pa and Pb, respectively, is
completed.
Thus, with the copying machine 1 equipped with the above described
recirculating document handling mechanism, and at the time the
duplex copying operation is carried out, the first document can be
transported to the document inverting means after an image of one
side of the first document has been copied, and, on the other hand,
a copying of an image on one side of the second document is carried
out while the copying sheet having one side copied with the image
is transported through the sheet inverting means towards the
intermediate tray. Therefore, the length of time required to
accomplish the duplex copying for making the duplex copies from the
duplex documents can be advantageously reduced.
The illustrated embodiment of the present invention is so designed
and so structured that the second-fed document can be transported
in pursuit of the first-fed document. As another example, if the
system is so designed and so structured to have an enough time
available between the timing at which the second document is moved
past the first reading station and the timing at which the first
document is subsequently moved past the second reading station and
also to have a space enough to avoid any possible collision between
the first and second documents within the document inverting means,
a third-fed document may be transported in pursuit of the
second-fed document, that is, three documents may be simultaneously
transported during the actual copying operation, thereby to reduce
the time required to complete the copying job.
The copying machine equipped with the recirculating document
handling mechanism of the present invention can be advantageously
applied when the duplex copies are desired to be made from the
duplex documents. In addition, the copying machine equipped with
the recirculating mechanism can also be applied in selectively
making simplex copies from simplex documents, duplex copies from
simples documents, and simplex copies from duplex documents and
these will be briefly described with reference to FIG. 1.
Where simplex copies are desired to be made from simplex documents,
that is, where information on one side of each document is desired
to be copied on one side of a copying sheet, the document D has to
be placed on the document tray 5 with the information bearing side
thereof oriented upwards as viewed in FIG. 1. After the document D
at the top of the stack of the documents has been drawn out from
the document tray 5, the information bearing side thereof is
scanned at the first reading station 7 and is then transported past
the second reading station 9 without being scanned, finally being
returned onto the document tray 5 from below. On the other hand,
after the information on such one side of the document which has
been scanned at the first reading station 7 has been duplicated on
one side of the recording paper P, the copying sheet P is ejected
onto the copy receiving tray 23.
In the case of the duplex copying from the simplex documents, in
which respective information on one side of each of the two
documents are copied on the opposite sides of a copying sheet, the
documents D have to be placed on the document tray 5 with their
information bearing sides oriented upwards. The respective
information bearing sides of the first-fed and second-fed documents
are, after having been moved past the first reading station 7 at
different times, scanned thereat and are then returned to the
document tray 5 from below without being scanned at the second
reading station 9. As far as the copying sheet P is concerned, the
copying sheet P, after one side thereof have been copied with the
image on the information bearing side of the first-fed document Da,
is delivered through the sheet inverting means 20 to the
intermediate tray 5. Thereafter, the copying sheet P is again
supplied from the intermediate tray 21 onto the transfer station so
that an image on the information bearing side of the second-fed
document Db which is scanned at the first reading station 7
subsequent to the scanning of the first-fed document Da can be
copied on the other side of the same copying sheet P. Then, the
copying sheet having its opposite sides copied with the images on
the respective sides of the first-fed and second-fed documents Da
and Db is subsequently ejected onto the copy receiving tray 23.
In the case of making simplex copies from duplex documents, that
is, where images on the opposite sides of each document are desired
to be copied on respective one sides of two copying sheets, the
duplex documents have to be placed on the document tray 5. After
the uppermost document D has been drawn out from the document tray
5, the opposite information bearing sides of the document D can be
scanned at the first and second reading stations 7 and 9,
respectively. The documents having its opposite sides scanned is
returned to the document tray 5 from below. On the other hand,
after the image on one side of the duplex document D has been
copied on the copying sheet P, such copying sheet P can be ejected
onto the copy receiving tray 23.
Thus, according to the present invention, since during the copying
operation, the successive transportation of the documents through
the document transport passage means within the recirculating
document handling mechanism parallels the transportation of the
copying sheets which are equal in number to the number of the
documents being transported and which are moved along the transport
passage means within the machine housing, the length of time
required to complete the copying job can be advantageously reduced,
permitting the operator to maximize the utilization of a time.
Although the present invention has been fully described in
connection with the preferred embodiment thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications are apparent to those skilled in the art without
departing from the scope of the present invention as defined by the
appended claims. Such changes and modifications are to be construed
as included within the scope of the present invention.
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